Laser apparatus is usually part of an optical system for performing some operation using the laser apparatus. Such operations include laser machining, optical inspection of semiconductor circuits, interferometry, and microscopy. Because of this, there is a constant demand to reduce the size of laser apparatus, for example, for correspondingly reducing the size, or for increasing the portability of the overall optical system.
One approach to reducing the size of laser apparatus is described in U.S. Pat. No. 7,952,806, assigned to the assignee of the present invention and the complete disclosure of which is hereby incorporated by reference. In this apparatus the output of four semiconductor lasers, each emitting radiation of a different color is combined to provide illumination for microscopy. The apparatus is housed in an enclosure divided into three compartments arranged one above another. Lasers are located in a base compartment, electronics are located on the floor of the next compartment, and a beam combining arrangement including a compact, monolithic, pentagonal beam-combining prism is mounted on the floor of the upper compartment.
A limit to compactness in this arrangement is that the area of footprint of the enclosure is determined by the area required of the biggest compartment. Vertical floor-spacing is determined by the tallest compartment on any one floor. In order to achieve any further compacting, a more flexible approach to such housing or packaging is required.